Snubbed truck



y 1961 c. E. TACK ETAL 2,986,101

SNUBBED TRUCK Filed Feb. 2, 1959 4 Sheets-Sheet 1 a l W J i 0 i 20 5 57May 30, 1961 c. E. TACK ETAL SNUBBED TRUCK 4 Sheets-Sheet 2 Filed Feb.2, 1959 hi fl l l U. a

y 0, 1961 c. E. TACK ETAL 2,986,101

SNUBBED TRUCK File Feb- 2. 1959 4 Sheets-Sheet a y 1961 c. E. TACK EI'AL2,986,101

SNUBBED TRUCK Filed 2, 1959 4 Sheets-Sheet 4 United States PatentSNUBBED TRUCK Carl E. Tack, Chicago, and Fred E. Bachman and Arthur F.Baker, Granite City, [1]., assignors to American Steel Foundries,Chicago, Ill., a corporation of New Jersey Filed Feb. 2, 1959, Ser. No.790,758

23 Claims. (Cl. 105-197) This invention relates to railway car trucksand more particularly to a novel snubbed bolster truck wherein frictionmeans are provided for damping vertical and horizontal oscillation ofthe bolster relative to the side frames affording spring-support for theends of the bolster.

A primary object of the invention is to devise a snubbed truck in whichthe friction means may be quickly and easily assembled and disassembledwith the bolster resting on its supporting springs.

A more specific object of the invention is to enable a single operatorto assemble or remove the friction means from the outboard end of thebolster without jacking the latter from its supporting springs andwithout moving the bolster in any manner whatsoever.

Another object of the invention is to compress the actuating spring forthe friction means against a spring seat having a simple and effectivereleasable interlock with the bolster at its outboard end.

Still another object of the invention is to devise novel means forcompressing the actuating spring to enable release of the removablespring seat from the bolster.

The foregoing and other objects and advantages of the invention willbecome apparent from a consideration of the following specification andthe accompanying drawings, wherein:

Figure 1 is a fragmentary perspective view of a freight car truckembodying a preferred form of the invention, the view being taken fromone outboard end of the bolster;

Figure 2 is a fragmentary top plan view of the structure shown in Figure1 with the side frame columns shown in horizontal section and the springplate retainer key broken away;

Figure 3 is a sectional view on line 3-3 of Figure 2 illustrating use ofcam mechanism prior to insertion of y;

Figure 4 is a sectional view on line 4-4 of Figure 2;

Figure 5 is a fragmentary perspective view similar to Figure 1, showingthe application of a cam mechanism utilized in the assembly anddisassembly of the friction means;

Figure 6 is a fragmentary perspective View taken from the outboard endof the bolster with the friction means removed therefrom;

Figure 7 is a fragmentary perspective view similar to Figure l butshowing a modification of the invention;

Figure 8 is a fragmentary top plan view of the structure shown in Figure7;

Figure 9 is an elevation view taken on line 9-9 of Figure 8;

Figure 10 is a sectional view taken on line 10-10 of Figure 8;

Figure 11 is a fragmentary perspective view similar to Figure 1, butshowing another modification of the invention;

Figure 12 is a fragmentary top plan view of the structure shown inFigure 11;

2,986,101 Patented May 30, 1961 ice Figure 13 is a sectional view online 13--13 of Figure 12;

Figure 14 is an outboard end elevational view showing the structure ofFigure 11 with a tool applied to the bolster end for assembling anddisassembling the friction means;

Fig. 15 is a fragmentary perspective view similar to Figure 1, butshowing still another embodiment of the invention;

Figure 16 is a fragment top plan view of portions of a truck embodyingstill another form of the invention, and

Figure 17 is a front elevational view of the structure illustrated inFigure 16.

Describing the invention in detail and referring first to the embodimentthereof illustrated in Figures 1-6, the bolster, generally designated at2, is illustrated as a onepiece structure; however, it will be readilyunderstood by those skilled in the art, that if desired, the bolster maybe a composite structure composed of separable components which, whenassembled on the bolster supporting springs, oscillate as a unit. Thebolster is spring-supported as at 3 from a side frame 4.

The bolster comprises top and bottom walls 5 and 6 and spaced side walls8 and 9. The side walls and the top and bottom walls define an opening10 in the outboard end of the bolster 2 through which a friction shoe 12and its actuating spring 14 may be conveniently assembled anddisassembled, as hereinafter described, without the necessity of movingthe bolster in any manner whatsoever.

The shoe 12 extends through an opening 15 of the side wall 8 and bearsagainst a friction surface 16 of a side frame column 18. The shoe alsobears against a seat or web 20 of the bolster as best seen in Figures 2and 4. The web 20, as illustrated in Figure 4, is of the socalled doubleangle type defining a V between the top and bottom bolster walls 5 and6, thus interlocking the bolster 2 and shoe 12 against relative verticalmovement or chatter during oscillation of the bolster in service.However, it will be understood that if desired, the web 20 may be of theso-called single angle style, shown in US. Letters Patent No. 2,730,049issued on January 10, 1956, to Schlegel, or, if desired, the bolster web20 may be vertical or of any other suitable configuration.

The shoe comprises a spring seat 22 (Figure 2) facing the bolsteropening 10, and the seat 22 is engaged by the compression spring 14, theoutboard end of which is seated against a spring seat 26 removablyattached to the bolster 2 by a key 28 extending through slots orapertures in the top and bottom bolster walls 5 and 6. The key comprisesa head 30 for convenient handling and extends through a loop or strap 32of the spring seat 26. If desired, a retainer such as a pin (not shown)may be inserted through aligned openings (not shown) of the key 28 andthe strap 32 to prevent any possibility of accidental displacement ofthe key in service.

Reaction of the spring 14 through the shoe 12 and the bolster web 20urges the bolster transversely thereof into frictional engagement with afriction plate 34 on a column 36 of the side frame 4.

In assembling the friction device, the shoe '12 is inserted through thebolster opening 15 and is manually urged to the position shown in Figure2 in snug abutment with the bolster web 20 and the column surface 16.The spring 14 is manually seated against the spring seat 22 of the shoe12 and against the spring seat 26 in the position shown in Figure 3. Thespring 14 is then compressed by cam plates 37 which, as best seen inFigures 3 and 5, straddle the loop 32 and bear against the outboard sideof the spring seat 26. The cam plates 37 are inter-connected by atrunnion 38 which is releasably journaled in a socket 40 of a lug 42depending from the top bolster wall at the outboard end thereof. As bestseen in Figures 3 and 5, the socket 40 faces inboardly toward the springseat 26, whereby exertion of a downward force on a cam lever 44connected to the plates 37, the spring seat 26 is urged beyond theposition shown in Figure 3, thereby compressing the shoe actuatingspring 14 to a point whereat the key 28 may be dropped into assembledposition shown in Figures 1, 2, and 5 of the drawings. The cam lever isthen released so that the spring 14 urges the key 28 into tight abutmentbetween spring seat 26 and top and bottom bolster walls 5 and 6. Inreverse manner, the friction shoe 12 and spring 14 may be removed, asfor replacement or repair.

Referring now to Figures 7-10, inclusive, a modification of the noveltruck is illustrated, wherein parts corresponding to those previouslydescribed are identified by corresponding numerals.

In the modification, the opening in the outboard end of the bolster ispartly defined by vertical ribs 50 and 52, and compression of the spring14 is maintained by a readily releasable spring plate 54 received withina slot 56 in the top bolster wall 5. The plate 54 comprises a slot 58partly defined by spaced legs 60 and 62 received within complementaryapertures of the bottom bolster wall 6, as best seen in Figures 9 and10.

The friction device, consisting of shoe 12 and its actuating spring 14,may be quickly and conveniently removed by means of a bolt 66 having aT-head 68 which may be inserted through a complementary slot 70 of thefriction shoe and may be rotated 90 and retracted slightly to theposition shown in Figure 8 to interlock the head and the bolt againstrotation by engagement by the head 68 with lugs 72 of the friction shoe,as shown in Figure 8. Thereafter, a nut 74 on the bolt 66 may be rotatedby a wrench or other suitable tool (not shown) to compress the spring 14between the shoe spring seat 22 and a spring seat 76 sleeved on the bolt66 and slidably engaged with the nut 74. When the spring has beencompressed to a point at which the plate 54 can be lifted from thebolster slot 56 by means of a handle 78 on the top of the plate 54, thelatter is disassembled in this manner from the bolster and the spring 14and shoe 12, together with the bolt 66, the nut 74, and the spring seat76, may be pulled through the opening 10 in the outboard end of thebolster to completely disassemble the friction device without moving thebolster in any manner whatsoever.

In reverse manner, the friction shoe 12 and spring 14 can be assembledwith the bolster and when the nut 74 has been rotated to a point whereatall reaction of the spring 14, is transmitted to the bolster by thespring plate 54, as shown in Figure 10, the nut may be additionallyrotated to permit inward movement of the bolt to a point whereat thehead 68 is released from the shoe lugs 72 whereupon the bolt may berotated until the head can be pulled outwardly through the slot 70 sothat the bolt 66 and nut 74 may be completely removed from the truckwhereupon the latter is in condition for service. Accidental upwarddisplacement of the plate 54 under these conditions is prevented by anoverlying ledge 79 of the top bolster wall 5.

Figures 11-14, inclusive, illustrate another embodiment of the inventionand parts corresponding to those previously described are identified bycorresponding numerals.

In this modification the outboard end of the spring 14 is compressedagainst a spring seat 100 having one end received in a slot 102 of thebottom bolster wall 6. The spring seat 100 is seated against the bottomwall 6 along a ledge or shoulder 104 of the spring seat 100. The otherend of the spring seat extends upwardly through a slot or aperture 106of the top bolster wall 5. The spring seat comprises a ledge or shoulder108 underlying ignated at 120.

the top bolster wall 5, as best seen in Figure 13, to afford a positiveinterlock between the bolster and spring seat 100 preventing accidentalupward movement thereof in the assembled condition of the friction shoe12 and spring 14 shown in the drawings. In the event that the frictionshoe 12 or spring 14 should become broken in service, relieving the seat100 of spring pressure, it will be apparent that the seat 100 willremain in position preventing accidental loss of the spring or shoe fromthe opening 10 in the outboard end of the bolster. The only manner inwhich the spring seat 100 could accidentally become disassembled fromthe bolster in the event that the seat is relieved of spring pressurewould be if the spring seat 100 became seated at its lower end on thebottom bolster wall 6 in a perfectly vertical position with the ledge108 aligned with the forward edge of the aperture 106 at a time when thespring seat 100 is subjected to a perfectly vertical upward impact. Sucha combination of circumstances is so unlikely as to be almosthypothetical.

The bolster walls 5 and 6 are provided with a depending lug 110 and anupstanding lug 112, respectively, affording abutment for lugs 114 and116 of a yoke 118 constituting part of a screw type jack, generally des-The jack comprises a pressure block 122 having side plates 124 whichstraddle the spring seat 100 and engage the outboard end of the spring14, whereby upon rotation of a screw 126 threaded in the yoke 118 androtatably journaled at 128 in the pressure block 122, the spring 14 maybe compressed to a point whereat the spring seat may be manually removedthrough the slot 106 in the top bolster wall 105.

The friction device may be assembled by manually urging the shoe 12 andspring 14 to the position shown on Figure 12 and then compressing thespring 14 by means of the jack to a point at which the spring seat 100may be inserted through the bolster slot 106 to the position shown inFigure 13, whereupon the jack 120 is actuated to release its pressureagainst the spring 14 until the latter urges the spring seat 100 intotight engagement with the bolster within its apertures 102 and 106, asseen in Figure 13. Thereafter, the jack 120 may be moved laterally todisengage its lugs 114 and 116 from the bolster lugs 110 and 112.

Figure 15 illustrates another embodiment of the invention which issubstantially identical with that disclosed in Figures 11-14 hereofexcept that two friction devices, each consisting of a shoe 12 andspring 14, are provided; and a bolster mounted releasable spring seat100, identical with that described in Figures ll-l4, is utilized tomaintain pressure on each spring 14. It may also be noted that in theembodiment of Figure 15, the top and bottom bolster walls 5 and 6 areprovided with holes 130 for the purpose at anchoring an associated powertype jack (not shown) which may be utilized to compress the springs 14during assembly and disassembly of the friction devices substantially asheretofore described in connection with the embodiment of Figures 11-14.

Thus, it will be understood that the novel snubbed truck is simple andrugged in design, utilizing a minimum number of parts, with the frictiondevice readily removable from an opening in the outboard end of thebolster without the necessity of jacking the bolster from its supportingsprings or moving the bolster in any manner whatsoever. This greatlyreduces the time required to assemble and disassemble the frictiondevice and permits repair or renewal thereof under conditions where itwould otherwise be impossible to service the friction devices.

Figures 16 and 17 illustrate still another embodiment of the invention.It will be seen that the arrangement illustrated in these figures issimilar to that of Figure 15 except that the friction shoes 212 havebeen provided with extra large outer friction flanges 213 to affordgreater areas of frictional engagement between the bolster and the sideframe, and the bolster and side frame have been altered to accommodatethe use of these modified friction shoes.

As best seen in Figure 16, bolster side walls 208 and 209 terminate atthe rearward extremities of webs 220 so that forwardly of this point, oneach side of the bolster, there is an opening 215 provided between theupper and lower walls 205 and 206, respectively, of the bolster, whichextends all the way to the outboard end of the bolster.

As best seen in Figure 17, the flanges 213 of each shoe extend above andbelow the inner surfaces of bolster top and bottom walls 205 and 206 soas to preclude insertion or withdrawal through the bolster opening 215in the same manner that the friction shoes 12 of the other embodimentsof the invention are inserted or withdrawn through related bolsteropenings 15 of those embodiments. However, by extending the opening 215all the way to the outboard extremity of the bolster, it will be seenthat after the friction springs 214 have been removed in the same manneras those of the embodiments illustrated in Figures 14 and 15, thefriction shoes may be withdrawn from the bolster by sliding themstraight out along a line parallel to the longitudinal axis of thebolster.

In order to compensate for any loss of rigidity occasioned by theelongation of openings 215, there may be provided a vertical center wall207 which is formed integrally with, so as to interconnect, bolster topand bottom walls 205 and 206.

It will also be apparent from an examination of Figures 16 and 17 thatif the bolster were provided with conventional gibs disposed on oppositesides of side frame column 218, the outboard gib would preclude thewithdrawal or insertion of the flanged shoes 212 in the mannerpreviously described. Thus, in order to accommodate assembly of theshoes in this manner, the bolster has been provided with a pair of extralarge single inboard gibs which extend outwardly from side walls 208 and209 at the place of their merger with webs 220. Each inboard gib 230 isreceived w'thin a slot 232 presented by a generally L-shaped lug 234preferably formed integrally with the inboard side of related column218. It will be understood that the embodiment illustrated in Figures 16and 17 is basically the same in operation as the embodiment illustratedin Figure 15, and the friction device may be assembled and disassembledfrom the bolster in the same manner. A primary advantage of theembodiment illustrated in Figures 16 and 17, however, is thatsubstantially greater areas of frictional contact are provided betweenthe bolster and side frame by virtue of the enlarged friction shoeflanges; also the novel construction of the bolster side walls and gibspermits the use of shoes having such enlarged flanges.

We claim:

1. A railway car truck comprising a frame, a bolster structurespring-supported by said frame, an internal shoe seat in said structurearranged angularly to a friction surface on said frame, friction shoemeans bearing against said seat and surface, said shoe means having aspring seat facing an opening in the outboard end of said bolsterstructure, spring means compressed against said seat, and a spring seatseparable from and removably interlocked with said bolster structure,said separable seat engaging the outboard end of said spring means toreleasably maintain the latter under compression, the length and widthof said opening being greater than the height and width of the springmeans and shoe means, whereby said spring means and shoe means can beremoved through said opening upon disassembly of the separable springseat from said structure.

2. In a railway car truck, a frame, a hollow bolster structure having atop wall and a bottom wall springsupported by said frame, friction meansin the bolster structure engaged with friction means of the frame fordamping oscillation of the bolster structure, an opening in the outboardend of said structure between said walls, the opening being of greaterheight and width than that of said first-mentioned friction means, andmeans releasably interlocked with the bolster structure and disposedoutboardly of said friction means for preventing removal thereof throughsaid opening and said thirdmentioned means being readily separable fromthe bolster structure to permit removal of said first-mentioned frictionmeans from the bolster structure through said openmg.

3. In a railway car truck, a frame, a bolster structure spring-supportedthereby, friction means housed in said structure engaging friction meansof the frame to damp oscillation of said structure, an opening in saidbolster larger than the cross-sectional area of the first mentionedfriction means to afford passage thereof through said opening withoutmoving the structure in any manner whatsoever, and means releasablyinterlocked with the bolster for obstructing said opening and forholding the first mentioned friction means in engagement with the secondmentioned friction means.

4. In a railway car truck, a frame, a bolster structure spring-supportedby the frame, friction means housed in the bolster structure andprojecting through an opening thereof into frictional engagement withthe frame, a spring having a substantially horizontal axis, said springbeing compressed at its inboard end against the friction means foractuation thereof, and readily releasable means releasably interlockedwith the bolster structure for maintaining compression on the outboardend of the spring, said releasable means being movable vertically inunison with the bolster structure during vertical oscillation thereof.

5. A railway car truck according to claim 4, wherein the bolsterstructure and the pressure maintaining means are provided withinterengaging means preventing accidental disassembly of the pressuremaintaining means.

6. In a railway car truck, a frame, a bolster structure spring-supportedthereby, friction means housed in the bolster structure and havingfrictional engagement with the frame, spring means compressed at itsinboard end against the friction means for actuation thereof, readilyreleasable spring seat means releasably interlocked with the bolsterstructure and readily separable therefrom, the outboard end of saidspring means being compressed against said spring seat means and urgingthe latter into tight abutment with the bolster structure.

7. A railway car truck according to claim 6, wherein the spring seatmeans is assembled and disassembled with respect to the bolsterstructure by movement through an aperture in the top thereof, andwherein the spring seat means comprises a surface underlying a surfaceof the bolster to prevent accidental upward movement of the spring seatmeans from assembled position thereof.

8. In a railway car truck, a frame, a bolster structure spring-supportedby the frame, a friction shoe housed in the bolster structure infrictional engagement with the frame, a spring compressed against theshoe for actuation thereof, aspring seat maintaining compression on thespring, a plate releasably interlocked with the bolster structure andengaged with the spring seat, a slot in the plate, and means extendingthrough the slot releasably interlocked with the shoe and engaged withthe seat for compressing the latter against the spring to enabledisassembly of the plate from the bolster structure.

9. In a railway car truck, a frame, a bolster structure spring-supportedthereby, said structure comprising top and bottom walls and spaced sidewalls, one of the side walls being in frictional engagement with theframe, an opening through the other side wall, a friction shoe bearingagainst a surface of the bolster structure and extending through saidside wall opening and frictionally engaging the frame, a slot throughthe top wall, a plate engaged with the bolster and removable through theslot, 3. slot through the plate intersecting the bottom thereof, springmeans compressed between the shoe and the plate for actuation of theshoe, and means extending through the last mentioned slot connected tothe shoe and the spring means for compressing the latter to relievespring pressure against the plate and thereby accomodate removal thereoffrom the slot in the top bolster wall.

10. A railway car truck according to claim 9, wherein the platecomprises spaced legs partly defining its slot and received withinapertures in the bottom bolster wall.

11. A railway car truck according to claim 9, wherein the plateunderlies a surface of the top bolster wall to prevent upward movementof the plate when under pres sure by the spring means.

12. In a railway car truck, a frame, a bolster structurespring-supported by the frame, a friction shoe seated against a surfaceof the bolster structure and extending through an opening thereof intofrictional engagement with the frame, said shoe having an outboardlyfacing surface, a spring seat having an inboardly facing surface, springmeans compressed against said surfaces for actuation of the shoe, andreadily releasable means engaging and interconnecting the spring seatand the bolster structure for maintaining compression on the springmeans, the bolster having an opening in its outboard end larger than theheight and width of the spring means and shoe to accommodate removalthereof through said opening upon release of said readily releasablemeans from the bolster structure.

13. A railway car truck according to claim 12, wherein the readilyreleasable means comprises a key extending through a loop of the springseat and extending through openings of the bolster structure above andbelow said loop.

14. A railway car truck according to claim 13, wherein the bolsterstructure is provided with an abutment facing inboardly and engageablewith a tool for compressing the spring seat against the Spring to enabledisassembly of the readily releasable means from the bolster structure.

15. A railway car truck according to claim 13, wherein the readilyreleasable means are characterized by interengaged surfaces of thebolster structure and the second mentioned spring seat.

16. A railway car truck according to claim 15, wherein the spring seatis provided with an upwardly facing ledge underlying a portion of thebolster structure.

17. In a railway car truck having a frame member and a bolster memberresiliently supported thereon, friction means carried by one of saidmembers for engagement with a surface of the other member to damprelative vertical oscillation between the members, detachable springretainer means carried by said one member in releasable interlockingengagement therewith, said retainer means being spaced from saidfriction means, spring means carried by said one member and compressiblyinterposed between the friction means and the retainer means, saidspring means being operable to urge the friction means into engagementwith said surface and to resiliently urge said spring retainer meansinto said interlocking engagement with said one member, said one memberincluding means for releasably interlocking therewith a pressure deviceengageable with the spring means to compress the latter and permitremoval of the spring retainer means, the spring means, and the frictionmeans without chlanging the positions of the members relative to each oter.

18. In a railway car truck, the combination of: a side frame havingspaced columns defining a bolster opening therebetween and presentingopposed friction surfaces in said opening; a bolster having an endportion resiliently supported in said opening, said bolster havingvertically spaced top and bottom walls interconnected by side walls, andan internal wedge wall presenting a wedge surface, at

least one of said side walls presenting in said bolster end portion aslot open toward the outboard extremity of the bolster; a friction shoehaving portions disposed within and without said bolster, the outerportion of said shoe including a flange larger than said slot so as tobe removable from the bolster only by sliding it in the slot toward theoutboard end of the bolster; a spring compressibly abutting the innerportion of the shoe to urge it into engagement with the wedge andfriction surfaces; and readily releasable spring seat means carried bythe bolster in engagement with said spring.

19. In a railway car truck, the combination of: a side frame havingspaced columns defining a bolster opening therebetween and presentingopposed friction surfaces in said opening; a bolster having an endportion resiliently supported in said opening, said bolster havingvertically spaced top and bottom walls interconnected by side walls, andan internal wedge wall presenting a wedge surface, at least one of saidwalls presenting in said bolster end portion a slot open toward theoutboard extremity of the bolster; a friction shoe having portionsdisposed within and without said bolster, the inner portion including aspring seat and wall engageable with the bolster wedge surface, and theouter portion including a flange engageable with a friction surface ofthe side frame, and a spring compressibly interposed between the shoeand the bolster operable to urge the shoe into engagement with the wedgeand friction surfaces of the bolster and side frame, respecively, theslot in the bolster side wall permitting the removal of the shoe fromthe outboard end of the bolster.

20. In a railway car truck, the combination: a side frame having abolster opening and presenting a vertical friction surface therein; abolster resiliently supported in said opening, said bolster presentingan internal wedge surface diagonally related to the side frame frictionsurface, said bolster including a vertical side wall having a slottherein open at the outboard end of the bolster; a friction shoedisposed to extend through the slot, said shoe having an outer flangedportion disposed in engagement with said side frame surface and havingan inner portion including a wall disposed in engagement with thebolster wedge surface; and resilient means compressed against the shoeto urge the shoe into engagement with the wedge and friction surfaces ofthe bolster and side frame; said slot accommodating removal of the shoeendwise of the bolster.

21. In a railway car truck, a frame having a supporting surface and afriction surface, a bolster spring carried on the supporting surface andmovable adjacent said friction surface, said bolster having spacedabutments, a friction shoe disposed in said bolster and engaging thefriction surface, spring means abutting said shoe and urging said shoeagainst said surface, and seat means abutting the spring means and beingreleasably maintained thereby against the abutments of the bolster, saidspring means and shoe being removable from said bolster from betweensaid abutments upon release of said seat means from the abutments.

22. In a railway car truck, a frame, a bolster springsupported on theframe, said bolster comprising vertically spaced walls interconnected byside walls and defining therewith an opening in the outboard end of thebolster, a friction shoe disposed between the walls and having a portionextending through an opening in one of the side walls inboardly of thefirst-mentioned opening and engaging the frame, an abutment on one ofthe bolster walls spaced from said second-mentioned opening and facingsaid second-mentioned opening, a releasable spring seat releasablyengaging the abutment, a spring having its ends compressed against theshoe and seat respectively, and operable to maintain the engagement ofthe shoe with the frame and the engagement of the seat with theabutment, the shoe, spring, and seat being removable from between thewalls through said opening.

23. In a railway car truck, a side frame having spaced 9 verticalmembers, a bolster spring-supported by the frame and having a portiondisposed intermediate the members, said portion comprising verticallyspaced walls and a wedge wall interconnecting said spaced walls adjacentone of the members and angling outboardly therefrom, a friction shoedisposed between said spaced walls, said shoe having a wedge surface anda friction surface, said wedge surface engaging the wedge wall and saidfriction surface engaging said one member, a spring seat, interlockingmeans on said spaced walls outboardly of said wedge wall and releasablyengaging the seat to interlock said seat with said bolster, and springmeans interposed be- 10 tween the shoe and the seat and urging saidwedge surface into said engagement with the wedge wall and also urgingsaid friction surface into said engagement with said one member, saidshoe and spring means being removeable 5 from the outboard end of thebolster upon release of said seat from said interlocking means.

References Cited in the file of this patent UNITED STATES PATENTS 102,485,508 Pierce Oct. 18, 1949 2,669,944 Spenner Feb. 23, 1954 2,688,938Kowalik Sept. 14, 1954 UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent No. 2,986,101 May 30, 1961 Carl E. Tack et ale It ishereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column l line 54, for "af" read of column 7, line 7, for "accomodate"read vaccommodate column 8, line 19, after "said", first occurrence,insert side lines 28 and 29, for "respecively" read respectively line31, after "combination" insert of Signed and sealed this 14th day ofNovember 1961.

(SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of PatentsUSCOMM-DC

